Method of manufacturing flanged sheet metal articles



Aug. 6, 1940. c, L, cKsoN 2,210,654

METHOD OF MANUFACTURING FLANGED SHEET METAL ARTICLES Filed June 30, 1959 3 Sheets-Sheet 1 fiderz arx raz-Zes Z 266% son.

1940- c. 1.. DICKSON 2,210,654

METHOD OF MANUFACTURING FLANGED SHEET METAL ARTICLES Filed June so, 1939 s Sheets- Sheet 3 Patented Aug. 6, 1940 UNITED STATES- METHOD OF MANUFACTURING FLANGED SHEET METAL ARTICLES Charles L. Dicks0n,.Harvard, Ill., assignor. to Starline, Inc Harvard, 111., a corporation of Illinois 7 Application June 30, 1939, Serial No. 282,303

8 Claims. (01. 113116) My invention relates to a method for the manufacture of generally rectangular shaped sheet metal articles having flanges extending continuously around their marginal edges.

More especially it relates to the manufacture of such articles as the bottom plates of livestock-water tanks (though the invention is not limited thereto), which, to meet trade demands, must be provided of a large number of sizes, the bottom plates being united with the side-wallforming portions of the tanks by folding together the flanges on these plates and outwardly extending flanges on the lower edges of the side-wallforming portions, producing seams.

In this connection, it may be noted that these water tanks to fill the demand are required to be provided in from about 75 to 100 sizes and in the past the flanged edges on the bottom sheets thereof were formed on hand machines, the radii of the corners being equal to one-half the width of the tank regardless of its width, thereby producing so called round end tanks and necessitating correspondingly different curvatures at the ends of the bottom plates for the different widths of tanks.

Were these rounded-end sheets for tanks of different sizes to be flanged on corner-flanging dies it would require not only the use of a great many of the dies to take care of the different number of sizes of sheets but, in View of the fact that it is not economical to carry a large stock of any one size of tank, short runs of the dies for each size of tank, requiring frequent changing from one die to another, would have to be made, which would make the operation a very expensive one.

Certain of the objects of my invention are to produce tanks of a desired rounded form at their vertical corners and having larger capacity than the rounded end tanks as commonly provided, which may be manufactured of different lengths and widths at less cost than in the case of rounded end tanks; to provide a novel method of producing round-corner sheet metal articles, particularly the bottom forming sheets of tanks of different widths; and other objects as will be manifest from the following description.

Referring to the accompanying drawings:

Figure 1 is a perspective view of a round cornered tank the bottom sheet of which is produced in accordance with my novel method.

Figure 2 is a perspective view of the blank from which the bottom sheet of the tank is produced, the corners of the sheet'being shown rounded in full lines, the material cut from the sheet in forming the round corners being shown by dotted lines.

Figure 3 is a similar View showing one of the steps in the production of the flanged bottom sheet.

Figure 4 is a similar view showing the completed bottom sheet.

Figure 5 is a view in vertical sectional elevation of a die machine which may be used in practicing my improved method, the section being taken at the-line 5 on Fig. 8, and viewed in the direction of the arrow.

Figure 6 is a fragmentary View of the structure shown in Fig. 5 showing themale die member in the position it assumes upon completing the cut ting operation at the corner of the sheet.

Figure 7 is a similar view of the same construction showing theposition of the die upon completing the flange-forming operation on the rounded corner of the sheet.

Figure 8 is a plan view of the female member of the die mechanism.

Figure 9 is a bottom plan view of the male die member of the mechanism.

Figure 10 is a fragmentary view in vertical section of the bottom sheet and the side wall forming portion of the tank, showing the form in which these parts are provided and the relative positions they assume upon initial assembly.

Figure 11 is a similar View of the structure shown in Fig. 10 showing a step in the operation of connecting the bottom sheet with the side wall forming portion by a folded seam; and

Figure 12, a similar View showing the final step of folding the parts into seam form.

In accordance with mynovel method the tanks produced instead of having rounded ends as above referred to are rounded only at their vertical cor ner edges as represented at l3 of the tank shown at M in Fig. 1, the arcs of curvature. of the rounded corners l3 being the same for all lengths and widths of the tanks produced; accordingly the flanged sheets, one of which is shown at I5 in Figs. 1 and 4, to form the bottoms of the tanks are similarly rounded at their corners, as represented at It, the arcs of curvature of such rounded corners being the same for all lengths and widths of plates.

In the practice of my improved method the metal sheet which is to be provided with a continuous upstanding flange about its margins as represented at I! of the sheet 15, with its corners rounded, as for example to form the bottom sheet of a tank, is provided of rectangular form, as shown by the straight full lines and the extension dotted lines in Fig. 2, and of such size that when flanged as stated it will be of proper size for assembly with the sheet for forming the side-wallforming portion of the tank, to form a tank of the desired size.

In the forming of the continuously flanged sheet the rectangular shaped blank referred to is first cut at its corners, in succession, to round these corners as indicated at 18, the arcs described by these rounded corners being the same.

In accordance with the preferred way in which my invention may be practiced each of the angular corners of the sheet may be cut to the desired rounded shape, by operating thereon, in succession in a single die mechanism such as that hereinafter described.

The next operation is to form the flanges I! on the straight sides and ends of the sheet. This may be done in any desirable way as for example by means of an ordinary sheet metal brake or by running themthrough a set of roller dies, as will be readily understood by those skilled in the art.

The sheet flanged as stated and as shown in Fig. 3 is then subjected to a forming action at its corners, in succession, to continue the flange around the curved corners of the sheet to produce the continuously flanged sheet as shown in Fig. 4. This is accomplished by the use of forming mechanism which in accordance with the preferred way of practicing my invention, is the same apparatus that is used, as above explained, in cutting the corners to rounded form.

It may be here stated that in accordance with the manner of uniting the bottom sheet [5 with the side wall portion IQ of the tank, by a folded seam, as is the usual practice in tank construction, the lower edge of the sid-e-wall-forming portion 19 is continuously flanged as represented at 20 and lies within the confines of the continuous flange I! as shown in Fig. 10, and that in the forming of the scam the flange H is folded inwardly and downwardly over the flange 29 as shown in Fig. 11, whereupon these flanges, together with the marginal edge of the sheet I 5, are folded upwardly, as a unit, to extend along the outer surface of the side-wall-forming portion IS.

The mechanism shown for blanking the corners of the sheet to rounded-form, and after forming the flange ill on the straight sides and ends of the sheet as stated, completing the flanging of the sheet by fianging the rounded corners thereof, comprises a female die member represented generally at 2! and a male die member represented generally at 22. V

The female die member 2! comprises a base plate 23 having guide posts 24, an arcuate shearing-die member 25, and an arcuate forming-die member 26 concentric with the member 25 and spaced therefrom as shown to provide an arcuate groove, or recess, 2'1 therebetween. The arcuate shearing edge of the shearing die member 25 is represented at 28 and the arcuate transversely curved forming edge of the die member 26 is shown at 29, the upper surface of the forming-die member 25 being located in a plane below the upper surface of the shearing-die member 25.

Secured to the base member 23 at opposite ends thereof is a pair of work centering stops 36 and 3| disposed at a right angle to each other and lined up with the ends of the shearing edges 28 of the die member 25, the guides 30 and 3| serving to properly position the sheet in the die mechanism in both the corner-blanking operation and in the operation of flanging the resultant rounded corners; the position occupied by the corner of the sheet preparatory to the blanking operation being represented by the dotted lines in Fig. 8.

The male die member 22 comprises a head 32 provided with an upstanding cylindrical portion 33 as usually provided on the movable die members of die presses and through the medium of which the die member 22 is reciprocated relative to the die member 2|; and has guide openings 34 at which it slides on the posts 24.

The die member 22 also comprises an arcuate male die element 35 carried by the head 32 to depend therefrom, the die member 35 being a combined shearing, or blanking, and forming die presenting the arcuate shearing edge 36 and the arcuate flange-forming edge 31.

The arcuate die member 35 is concentric with the shearing edge 28 and forming edge 29 of the die member 2|, its shearing edge 38 being disposed substantially directly in line with the shearing edge 28 to cooperate therewith to cut the corners of the sheet to rounded form as shown in Fig. 6, and its forming edge 31 slightly olfset radially outwardly from the forming edge 29 to flange the rounded corners of the sheet as shown in Fig. 7.

In the use of the mechanism shown the corners of the sheet to be rounded are introduced, in

succession, into the mechanism to the dotted position shown of one of the corners in Fig. 8

in which position the corner of the sheet overlies flanging operation just stated the die member 35,

as will be noted, penetrates quite deeply into the recess 29, as compared with the position it occupies upon completing the blanking of the corners of the sheet as shown in Fig. 6, such differential movements of the die member 35 being provided for by regulating the stroke of the die member 22 as will be understood by those skilled in the art.

It has been found in practice that by first rounding the corners of the sheet and then flanging its straight ends and sides, and thereafter flanging the rounder corners, the continuous flange formed about the sheet is sufliciently regular in form throughout its extent as to render it highly suitable for its intended purpose.

Furthermore, as will be readily understood, the use of a single die mechanism for blanking the corners into rounded form and flanging them, is of great. importance in minimizing the cost of manufacture of flanged sheets and particularly in those cases where the sheets are to form the bottom sheets of water tanks provided of different widths and lengths. All of the corners of the sheets of difierent widths and lengths, being rounded to describe arcs of the same radius, the blanking of the corners to rounded form and the fianging thereof, regardless of their width or length, may be effected on single die mechanism, using the same shearing and forming die elements for all lengths and widths of sheets; this being a great factor in the economical production particularly of stock-watering tanks.

While I have described a particular procedure constituting the preferred way of practicing my invention, and a particular mechanism for practicing the method, I do not wish to be undenstcod as intending to limit it thereto as the invention may be practiced in other ways and by other mechanism without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent, is:

1. The method of manufacturing flanged, round-cornered, sheet metal articles comprising subjecting the corners of the sheet of rectangular shape and from which the sheet article is to be made, to the action of a die machine for cutting the corners to rounded contour, flanging the straight edges of the sheet and thereafter subjecting the curved corner edges of the sheet to the action of the die machine in which the corners of the sheet were cut, for forming said corner edges into curved flanges extending along said curved corners.

2. The method of manufacturing flanged, round-corneredsheet metal articles comprising subjecting the corners of the sheet of rectangular shape and from which the sheet article is to be made, to the action of a die machine for cutting the corners in succession to rounded contour, flanging the straight edges of the sheet and thereafter subjecting the curved corner edges of the sheet to the action of the die machine in which the corners of the sheet were cut, for forming, in succession, curved flanges extending along said curved corners.

3. The method of manufacturing flanged, round cornered, sheet metal articles comprising cutting the corners of the sheet of general rec-- tangular shape and from which the sheet article is to be made, to rounded contour, flanging the straight edges of the sheet and thereafter dieflanging the curved corner edges of the sheet to form curved flanges extending along said curved corners, the edges of said cut corners being such that these edges, upon flanging the straight sides of the sheet are located inwardly of the points at which the lines of juncture of the straight side flanges with the sheet, would intersect, were such lines extended to intersecting position.

4. The method of manufacturing flanged,

round-cornered, sheet metal articles of different. widths comprising cutting the corners of all of the sheets of rectangular shape from which the various widths of sheet articles are to be made, to rounded contour, describing arcs of the same radius as to all of the sheets, flanging the straight edges of the sheets and die-flanging each sheet at its curved corner edges after its straight edges have been flanged, to form curved flanges extending along said curved corners, the edges of said cut corners being such that these edges, upon flanging the straight sides of the sheet are located inwardly of the points at which the lines of juncture of the straight side flanges with the sheet, would intersect, were such lines extended to intersecting position.

5. The method of manufacturing flanged, round-cornered, sheet metal articles comprising cutting the corners of the sheet of general rectangular shape and from which the sheet article is to be made, to rounded contour, flanging the intersecting position.

6. The method of manufacturing flanged, round cornered, sheet metal articles of different widths comprising cutting the'corners of all of the sheets of rectangular shape from which the various Widths of sheet articles are to be made, to rounded. contour, describing arcs of the same radius as to all of the sheets, flanging the straight edges of the sheets and die-flanging each sheet at its curved corner edges in succession after its straight edges have been flanged, to form curved flanges extending along said curved corners, the edges of said cut corners being such that these edges, upon flanging the straight sides of the sheet are located inwardly of the points at which the lines of junctureof the straight side flanges with the sheet, would intersect, were such lines extended to intersecting position.

'7. The method of manufacturing flanged, round-cornered, sheet metal articles comprising cutting the corners of the sheet of general rectangular shape and from which the sheet article is to be made, to rounded contour, flanging the straight edges of the sheet and thereafter dieflanging the curved corner edges of the sheet, and producing curved flanges at the corners of the sheet extending along said curved corners and merging into the adjacent straight flanges on the straight edges of the sheet and forming therewith an endless flange extending along the margins of the sheet, the edges of said out corners being such that these edges, upon flanging thestraight sides of the sheet are located inwardly of the points at which the lines of juncture of the straight side flanges with the sheet, would intersect, were such lines extended to intersecting position.

8. The method of manufacturing flanged, round-cornered, sheet metal articles of different widths comprising cutting the corners of all of the sheets of rectangular shape from which the various widths of sheet articles are to be made, to rounded contour, describing arcs of the same radius as to all of the sheets, flanging the straight edges of the sheets and die-flanging each sheet at its curved corner edges in succession after its straight edges have been flanged, and producing curved flanges at the corners of the sheet extending along said curved corners and merging into the adjacent straight flanges on the straight edges of the sheet and forming therewith an endless flange extending along the margins of the sheet, the edges of said cut corners being such that these edges, upon flanging the straight sides of the sheet are located inwardly of the points at which the lines of juncture of the straight side flanges with the sheet, would intersect, were a such lines extended to intersecting position.

CHARLES L. DICKSON. 

